Today an Eboot Fix for Call of Duty Modern Warfare 3 patch 1.21. It was orginally signed with for OFW 4.00 but with this Param.sfo and a few patches it will be up and running to work with the latest version of FckPSN. Check out the download and the tutorial below.
Tutorial:
1) Download official update 1.21
2) Then replace files in dev_hdd0/games/blus30838 with the fix pack
3) Play Online Via FckPSN